The present invention relates to an apparatus for adjusting the height of the upper fixing or guide fitting for the shoulder belt of a safety belt system, particularly in motor vehicles, with means for preferably automatically adapting the vertical position of the fixing or guide fitting to the sitting position of the person who is to wear the belt.
In German Offenlegungsschriften Nos. 26 25 417 and 28 34 837, various aspects are discussed with regard to the dependency of the vertical position of the fixing or guide fitting for the shoulder belt in a vehicle safety belt system on the horizontal and vertical position of the associated individual seat, and the aim, in terms of both the object and solution is to obtain the most favorable path of the safety belt from the fixing or guide fitting to the shoulder of the person in question. German Offenlegungsschrift No. 28 34 837 also states that the path of the belt is determined not only by the actual position of the seat, but also by the particular proportions of the individual wearer, which are characterized by the expressions "seated giant" and "seated dwarf".
In order to overcome the problem described in these specifications, it is proposed therein that each position of the seat in question be associated with a corresponding vertical position of the fixing or guide fitting, both as a function of horizontal adjustments of the seat, and also of vertical adjustments, so that, for example, a person with long legs and a short trunk, who will therefore adjust the seat to be far back and as high as possible, will have an associated upper anchoring point for the shoulder belt which is comparatively higher than would be provided for a person of normal build, who would also have the seat pushed back but not so high.
As a result of the strict correlation between the selected position of the seat in question and the vertical position of the associated fixing or guide fitting in the known apparatus, not only are those conditions with regard to physical proportions and/or the seat position which do not fit into the described scheme or are not to be subordinated to this scheme eliminated, but also the known proposed solutions require complicated and heavy constructions, which require considerable maintenance, the widespread introduction of which must appear questionable, if only on grounds of cost.
U.S. Pat. No. 4,039,224--Bauer et al dated Aug. 2, 1977 is also concerned with the problem of the favorable path of the safety belt from the shoulder of the wearer to the fixing or guide fitting on the body of the vehicle. This prior art relates to a passive buckling-on system, wherein the safety belt is automatically applied when the person has taken a position on the vehicle seat. Depending on the size and sitting position of the wearer, the fixing point for the safety belt located diagonally above the shoulder is appropriately determined and finally adjusted in one go. No further adjustments can then be made unless the person climbs out of the vehicle. The setting as such is obtained by means of a retaining member which moves in the direction of travel of the belt when the safety belt is automatically applied and thus engages a locking element. Since this latter element can only lock in a certain position, the setting in this known apparatus starts not from the belt but from the given locking position of the locking member. As a result, continuous adaptation to changes in the position of the wearer are impossible.
European patent application No. 00 24 446 discloses an apparatus for adjusting the vertical position of the upper fixing or guide fitting, wherein a lever is provided which is pivotable about an axis extending approximately in the longitudinal direction of the vehicle, in a plane at right angles to the longitudinal axis of the vehicle, while the tip of the lever on which the safety belt engages describes more or less a semicircle, when pivoted inside the vehicle, from the topmost to the lowest position. Admittedly, this enables the fixing or guide point to be brought into two or three different vertical positions, but the path of the belt is changed, in the transverse direction of the vehicle, so that, at worst, the belt will be brought into contact with the neck of the wearer. This could have very dangerous consequences, quite apart from the fact that the contact of the hard edge of the belt on the neck is uncomfortable.
It is therefore an object of the present invention to provide an apparatus for the purpose described hereinbefore, which makes it possible to determine the optimum path of the shoulder belt, independently of any given sitting positions, particularly simply, by means of manual setting, with the aid of a servomotor, or even automatically.